Telephone-exchange system.



M. L. JOHNSON.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION IV'ILBD AUGJO, 1912.

Patented sp't.1,1914.

4 SHEETS-SHBET 1.

FIG. 1

INVENTOR MORTON L .TJOHNSON WITNESSES ATTORNE M. L. JOHNSON.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED AUG,10,1912.'

1,109; 65 Patented Sept. 1, 1914.

4 SHEETS-SHEET 2.

wl'xnassas INVENTOB a 2 MORTON L.JOHNSOI\T I I' '1' Ear/Z4 M. L. JOHNSON. I

TELEPHONE EXCHANGE SYSTEM.

APPLIOATION FILED AUG. 10, 1912.

Patented Sept. 1,1914.

4 SHBBTE-QHBET 3.

'KMAfI F I M o grijz fhonnson ifl AT'IIIZ? M. L. JOHNSON.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED AUGJO, 1912.

1,109,165. Patented Sept. 1, 1914.

4 BHEETE-SHEBT 4.

WITN B65515 I 1G. 4 INVENTOR MORTON L. .JouNsoN 91 I I ATTORNEY omen salaries PATENT, cur os.

monron" L. JOHNSON, or cnIoAoo, ILLINOIS, Assrenon, BY lunsnn ASSIGNMENTS, r0 3mm B. coox'coiarnlw; or CHICAGO,- ILLINOIS, A ooRroRATIoN or rumors.

TELEPHONE-EXCHANGE sYs'rnM.

Specification of Letters Patent.- Application filed August 10,1912. seriaino. 714,419.

Patented- Sept. 1, 1 914,

To all whom; it may concern i Be it known that'I, MORTON L. JoHNsoN,

citizen of the United, States, residing at- Chicago, in the county ofCook and Stateof Illinois, have invented abertain new and useful Improvement in Telephone-.Exchan e Systems, of which-the following is a fu 1, clear, concise, and exactdescription, refer,-

ence being had to the'accompanying draw-' -ings, forming a part of this specification.

My invention relates to telephone ex- ..change systems. and has for one of its objects the provision of means for automatits details, the equipment illustrated being adapted to a one thousand line: system in which anoperator receiving a call may csica-lly signifying to operators the busy or idle condition of link connectors that are engaged by traveling Wipers passingnver.

Waiting contacts that constitute link connector terminals, the operators be1ng provided with means for arresting the wipers that engage the Waiting contacts of link connectors that are free for connection and are therefore free for use in establishing telephone circuits between calling and called lines. The signaling devices which may be employed in order to apprise the operator of the busy or idle condition of trunk lines over which calling line extending wipers of connecting switches pass may be of any suitable form, visual or audible. After the traveling wipers have been arrested bythe operator when in connection with an idle trunk line orlink connector, the operator may employ another device, lithe system be so designed, for e'fiecting the travel of. 35 wipers ofv another switch connected with the employed link connector further to extend the calling line.

I will explain myinvention more fully by reference to the (accompanying drawings showing the equipment which Ifemploy andFigs. 2-to 4,

inclusive,..taken collectively and-in numerical order, represent the system in more of tablish the entire connection between calling and called subscribers,-though the invention is not to be limited to the number of lines employed nor to the establishment of the final connection by *the operator between the preferred embodiment thereofand in whichi called line and the final link. connector selected by the receiving operator and brought into connection with a calling line.

j Referring first particularly to Fig. 1, I have thereshown (in the case of a one thousand l1ne system) a'subscribers station 111 in the first .group' of one hundred lines and which i'sset into operation by the equipment of a calling line and which is arrested when the waiting contacts peculiar to an idle oporator are encountered by the traveling wipers of the idle operator selector switch. Each operator selector switch 2 includes equipment, generally illustrated in Fig. 1 but more fully illustrated in the remaining figures, by which the switching apparatus 3 belonging to the selected idle operator is extended into connection with an operator controlled link selector switch 4. The Wipers of the selector switches 4 are shown as being individual to the subscribers lines though the invention is not to be thus re stricted. Each selector switch 4, in the system described, may be provided with ten levels of waiting contacts, each level having ten sets of waiting contacts. The lowest level of waiting contacts may extend to con nector switches 6 that are apportioned to the first group of one hundred lines,-the next level above may extend to connector switches 6that are apportioned to the second group of one hundred lines, and so on, the toplevel extending toconnector switches that are apportioned to the O-hun'dred group, the relationship of the waiting contacts of the switches 4; with each other and with the connector switches 6 being similar to the relationship that obtains between connector switches and .the next preceding selector switches in existing automatic telephone exchange practice which is exemplified in British Patent 1298 of 1910, the

mechanical structure being exemplified in Van Deventers Telephonology, page 530.

It is not to be understood, however, that I limit myself to the characteristics of the switches specifically set forth.

Assuming that the line 111 is the calling line. If the desired line is in the first group of one hundred, say line 112, the operator will raise the wipers of the switches 4 that are individual to the calling line 111 (though it is to be understood that the invention is not limited to switches 4 that are individual to the lines) to the first level of contacts and these wlpers in moving over these contacts will, when encountering contacts belonging to an idle link 7, effect the closure of a test circuit which includes a test device 5 that may be both visual and audible. "When the wipers 4 encounter waiting contacts belonging to an idle link 7 (these wipers moving sufliciently slow to permit of the operation to be mentioned), the operator will employ a device 3 for arresting these wipers in contact with the waiting contacts of such idle link 7. After having arrested the wipers of the switch 4 in connection with an idle link 7 the operator will employ the device 3 (which was used to effect the operation of the wipers of the switch 4 individual to the calling line) to eflect the operation of a connector switch 6 individual to the operator selected idle link 7, each link 7 having I a connector 6 individual thereto and each link having multipled contacts in the switches 4 in the system shown. After the wipers have been raised to the desired level they are preferably stepped around automatically but the invention is not to be thus limited.

The invention will now be further explained in connection with Figs. 2 to 4 inclusive, in which I have illustrated the equipment associated with the two lines (111 and 112) in the same group of one hundred lines. Each telephone station illustrated includes a telephone switch hook 8 having a normal contact serving, when the telephone receiver 9 is upon the switch hook, to establish a bridge connection between the line sides that includes a signal bell 10 and condenser 11. The switch hook has an alternate contact serving, when the telephone receiver is removed therefrom, to complete the metallic bridge connection between the line sides that includes the telephone receiver 9 and the telephone transmitter 12. Each line terminates at the exchange in the armature switches. of a cutoff relay 13 whose normal contacts are connected with the intermediate armature switches of a switching relay 14, the normal contacts of these latter armature switches being connected with the upper and lower windings of a line relay 15, the lower winding being directly grounded while the upper winding is grounded through the common battery 16. The line relay 15 is thus included in a closed circuit when the telephone receiver at a calling station is removed from its switch hook. When the relay 15 is energized a circuit is established which may be traced from its upper grounded armature switch, the alternate contact of such armature switch, the sluggishly operating interrupter relay 17, rotary magnet 18, the side switch wiper 19 in its first position, to the grounded common battery 16. The rotary ma et 18 now sets the wipers 20, 21, 22, 23, 24, 25, 26 and 27 into step by step movement until the wiper 22 encounters an ungrounded waiting contact whereupon all of these wipers are stopped, since the circuit for the private magnet 28 (which circuit was established upon the initial operation of the rotary magnet 18), is opened at the wiper 22, said private magnet then causing the side switch wipers 19 and 29 to step to their second positions. When the side switch'wiper 19 steps into its second position circuit for the rotary magnet 18 is opened. When the side switch wiper 29 is stepped to its second position the associate wiper 22 is grounded so that the contact engaged by this wiper 22 is grounded whereby other operator selector switches 2 having contacts in multiple with waiting contacts of the wiper 22 will not permit their wipers 5 22 to rest upon those waiting contacts that are in multiple with the waiting contacts thus grounded through the side switch wiper 29 of an employed operator selector switch. The other wipers of the operator selector switches are provided with waiting contacts, the contacts of each set in each switch being multiply related with similar contacts of other switches. The operators telephone 1 has telephone conductors provided with multiply related contacts provided for the wipers 20 in the different operator selector switches and multiply related contacts provided for the wipers 21 in the different operator selector switches, whereby the wipers 20 and 21 that are brought to rest connect some operators telephone set 1 with the calling line. The calling subscriber tells the operator the number of the desired line and the operator thereafter manipulates a suitable circuit interrupter device, simply shown as a key 3, for interrupting the circuit of the line relay 30, the circuit for this relay having been previously established due to a circuit from the grounded battery 16, the side switch wiper 19 in-its second position, the relay 31, the lowermost armature switch of relay 15 to ground, the upper armature switch of the now energized relay 31 establishing a circuit which may be traced from the upper winding ofrelay 30, the upper armature switch of relay 32 and its normal contact, the upper armature switch of relay 31 and its then engaged contact, the wiper 23 and its then engaged contact, the circuit tion, the next to the lowermost armatureinterrupting device 3, the wiper 24 and its then engaged contact, the next lower armature of relay 31, the intermediate armature switch of relay 32, the lower coil of relay 30, the grounded battery 16, to ground. The relay 30 is, by Blends of the device 3, operator controlled and whenever the device 3' is actuated the circuit for the -relay 30'is broken, whereupon the lower armature of the relay 30 engages its normal contact to establish a circuit from this lower armature, which is grounded, the normal contact of such armature, the lower armature switch of sluggishly operating relay 33 (whose circuit was previously established when the relay 30 was energized, as willbe apparent) the alternate contact of this latter armature switch, the sluggishly operating relay 34,

the vertical magnet 35, the side switch wiper 36 in its first position, the common battery 16, to ground. The vertical magnet 35 is thus operated as. often as the operator desires to causethe arbitrary movement of the wipers 37 38 and 39 to the desired level of ten contacts pertaining to the link connectors 7 apportioned to the group of one hundred lines. in which the desired line is in-' cluded. After this level has been arbitrarily selected by the operator the private magnet 40 is deenergized, this magnet 40 having. been energized upon the energization of relay 34,. the circuit for the magnet 40 having been preserved during the series of impulses conveyed by the operator owing to the sluggishness of the relay 34. Whenthe private magnet 40 is denergized the side switch wipers 36, 41 and 42 are stepped into their second positions, the wiper 36 establishing circuit for the rotary magnet 43 and opening the circuit for the vertical magnet 35, the rotary magnet then stepping the wipers 37, 38and 39 over their waiting contacts until the wiper 38 is in engagement with. a contact button that is free of direct connection to ground, these contacts being permanently connected to ground through a battery 16 and a resistancecoil 44, the battery 16 being effective, as it is then unshunted,

when the buttons of the wiper 38 are free of direct connection to ground. The buttons of the wiper 38 are directly connected to ground when the associate link connectors 7 are busy by way of the ground established by the intermediate armature switch of re-'' lay 45 of the connector switch 6 belonging.

to the busy link 7. Under the assumption that the link is not busy the ground at the upper armature switch of relay 45 is not present so that current frombattery 16 is not shunted directly to the same but finds a circuit which is traceable from-said battery 16through the resistance44, the wiper 38 and the waiting contact engaged thereby, the side switch wiper 41 in its second posi- -.switch of relay 31, the wiper 26 and itsthen engaged contact, the relay 46, to ground. The lower armature switch of relay'46 then closes circuit for the visual busy test signal device 47, such as a lamp, and the upper armature switch of this relay 47 including the busy test tone device 48 in circuit with the primary 49 belonging to the operator having the signaldevice 47. The operator thus receives double 'notification that the link 7 whose contacts are then engaged by the wipers 37, 38 .and 39is idle whereu on the operator depresses a key 50 to .establ a circuit which may be traced from the grounded contact of this key and its complemental. contact, the wiper 27 and its then enish gaged waitin contact, the lowermost arma- I ture switch 0 relay 31, the relay 51, the battery 16, to ground. The lower armature switches of relay 51 thereupon open the circuit of private relay 40 whereby the side switch wipers 36, 41 and 42 are stepped into their third positions, whereby the circuit of the rotary magnet'43 is opened at the side switch wiper 36 so that the wipers 37 38 and 39 are arrested from further progress, this stoppage of "the wipers being arbitrarily efiected by the'operator inresponse to the notification-that the link connector 7 now engaging the wipers 37, 38 and 39 is idle. It maybe said. in passing that circuit for the private magnet 40 was established when the s de switch wiper 42 was in its second posit1on due to the factthat the sluggishly operating relay 52 holds up its armature during the time the wipers37, 38' and 39 are moving.

It will be understood that the interrupter 53 serves'automatically to open and close the circuit of the rotary magnet 43.

The circuit of the private inagneti'gkIO may be traced from the grounded armatureswitch of relay 52, the side switch wiper;.42 in itssecond position, the lower armature switch of relay 51, the magnet 40, the. common but tery 16, to ground. When the wipers 37, 38

and 39 are arrested,-- the side switch wipersbeing in their third positions,-a circuit is established WhlCh is traceable from the ground ed battery 16 through the side switch wiper 1 36 in its third position, the windingof relay.

'32, the upper armature switch of sluggishly operating relay 33, to ground. When the y I relay 32 is energized the wipers. 37 and 39- are connected with-the key3 and the switch of relay 30 is opened to cut out the equipment of the selector switch 4 that was employed to connect the idle link connector 7. The ground at the upper armature switch of relay 33 is now removed but it is immediatelv replacedby the ground of-intermediate armature switch of relay 45' of the employed connector switch 6, the ground being established at the intermediate armature switch of relay 45 owing to the energization of the relay 54 whose circuit is established throughthe arrested wipers 37, 39 and the alternate contacts of the upper armature switches of relay 32 and the key 3. Therelay 54 of the employed connectorswiteh 6 is now within 12.17118 control of the operator who manipulates the key 3 to bringthe wipers 55, 56 and 57 "f the employed connector switch 6 up to their proper level and into engagement with the Waiting contacts of the desired line.

i It will be unnecessary .to describe in detail the connector switch which is employed as a i' suchisgfamiliar to those skilled in the art.

In order that the connector switch illustrated may be compared with the prior art some of the parts illustrated will be mentioned. The switch includes a vertical magnet 58, a rotary magnet 59, a ringing relay 60, armature switches 61 and 62 of the ring ing relay, ringing generator 63, busy tone device 64, 'privatecontrol relay 65, private relay 66', back bridge relay 67, ringing cutoff relay 68, an impulse control relay 69, side switch wipers 70, 71, 72 and 73, release mag- -i-:la'st', time to bring the wipers of the employed' connector switch into engagement with-the waiting contacts of the desired line the operator depresses the key 76 (this result may automatically follow the operation of thekey 3 if desired) whereby a circuit is established which may be traced from the "grounded battery 16 through the contacts of key 76, the wiper and its then engaged waiting contact, the middle armature switch of relay 31, the relay 14, the side switch wiper'41 in its third position, the wiper 38 and its then engaged contact to the then grounded intermediate armature switch of relay 45 of the employed connector switch 6. Therelay 14 when energized establishes a locking circuit for itself which is traceable w d-from" "the grounded common battery 16 through the lower armature switch of relay 14 and its then engaged contact, the winding inf-said relay 14, the side switch wiper'41 in its third position, the arrested wiper 38 and its then engaged contact to the then grounded intermediate armature switch of relay 45.

\ WVh'en the relay 14 is energized circuit for the relay 15 is opened at. the intermediate armature switches of relay 14, the uppermost armature switch of relay 15 then estab-- lishinga eireiut which may be traced from.

this uppermost armature switch which is grounded, the normal contact of such armature switch, the release magnet 77, the previously closed off normal switch 78, the battery 16, to ground. When the circuit of the release magnet 77 is established the wipers 19 to 27 inclusive and 29 are restored to normal. The calling line is now connected directly with the link leading to the wipers of the employed selector switch 4 independ ently of the operator selector switch 2. When both receivers at the calling and desired stations are upon their switch hooks the circuit of relay 45 is opened causing the removal of the ground at the intermediate armature switch of this relay 45, Wherebycircuit for relay 32 of the employed switch 4 is broken and the circuit for the relay 14 is also broken whereby all of the equipment is restored to normal. When the circuit of relay 32 is broken a circuit is established for the release magnet 7 9 of the employed switch 4 which may be traced from the grounded armature switch of relay 30, the lower armature switch of relay 33, the lower armature switch of relay 82, the release magnet 79, the previously closed oil normal switch 80, the battery 16, to ground. When the release magnet 79 is energized the wipers 36, 37, 38, 39, 41 and 42 are restored to normal. The circuit for the release magnet 74 of the connector switch is established in the usual way by the lowermost armature switches of relays 54 and 45 whereby the employed connector switch 6 is restored to normal.

In Figs. 2 to 4, inclusive, I have particularly described a connection initiated at statioh 111, the apparatus described being shown atthe upper portion of the figures. At the.lower portions of the figures I have shown similar equipment and similar parts are given similar characters of reference.

Cross reference is made to my co-pending application Serial No. 709,430, filed July 15, 1912 wherein I have disclosed a system employing operator controlled electro-magnetlc switching mechanism for extending calling lines into connection with operator selected link connectors.

While I have herein shown and particularly described the preferred embodiment of my invention, I do not wish to be limitedto the precise details of construction and c1rcuit arrangement shown as changes may readily be made without departing from the spirit thereof, but 0 Having thus described my inventlon I claim as new and desire to secure by Letters Patent the following 1. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; electromagnetic switching devices for connecting said link connectors with calling lines and including-traveling wipers and waiting contacts; testing means jointly governed by the link connectors and electromagnetic switching devices for enabling operators to determine the busy or idle condition of the link 7 erated connector switches for connecting change for extending calling lines; electromagnetic switching devices for connecting said link connectors with calling lines and including traveling wipers and waiting contacts; testing means jointly governed by the link connectors and electro-magnetic switch ing devices for enabling operatorsto determine the busy or idle condition of the'link connectors as the electro-magnetic switching devices operate; operator controlled means for arresting the switching devices when in association with idle link connectors; and operator controlled electro-magnetically opsaid electro-magnetic switching devices, that are connected with operator appropriated link connectors, with desired lines.

3. A telephone exchange system including telephone. lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; electromagnetic switching devices for connecting said link connectors with calling lines and including traveling wipers and waiting contacts; testing means jointly governed by the link connectors and electro-magnetic switching devices for enabling o erators to determine the busy or idle con ition of the link connectors as the electro-magnetic switching devices operate; operator controlled means for arresting the switching devices when in association with idle link connectors; oper-.

ators responsive devices at differentoperators positions; and selecting mechanism for selecting operators responsive devices that are free for selection.

4. Atelephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; electromagnetic switching devices for connecting said link connectors with calling lines and including traveling wipers and waiting contacts; testing means jointly governed by the link connectors and electro-magnetic switching devices for enabling operators to determine the busy or idle condition of the link connectors as the electro-magnetic switching devices operate; operator controlled means for arresting the switching devices when in association with idle link connectors; operator controlled electro-magnetically operated connector switches for connecting said electro-magnetic switching devices, that are connected with operator appropriated link connectors, with desired lines; operators responsive devices at different operators positions; and selecting mechanism for selecting operators responsive devices that are free for selection.

5. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling l1nes; electromagnetic switching devices for connecting said link connectors with calling l nes and including traveling wipers and waiting contacts; testing means jointly governed by the, link connectors and electro-magnetic switching devices for enabling operators to determine the busy or idle condition of the link connectors as the electro-magnetic switching devices operate; operator controlled means for arresting the switching devices when in association with idle link connectors; operators responsive devices at difierent operators positions; and selecting.

mechanism for selecting operators responsive devices that are free for selection, the link connectors performin their line joining functions independent y of said selecting mechanism that selects operators responsive evices.

' 6. A telephone exchange system including telephone lines extending from stations to an exchange; link connectors at the exchange for extending calling lines; electromagnetic switching devices for connecting said link. connectors with calling lines and including traveling wipersand waiting contacts; testing means jointly governed by the link connectors and electro-inagnetlc switching devices for enabling operators to determine the busy or idle condition of the link connectors as the electro-niagnetic switching devices Operate; operator controlled means for arresting -the switching devices when in association with idle link. connectors; operator controlled electro-magnetically operated connector switches for connecting said electro-magnet c switching devices,- that are connected with operator appropriated link connectors, with desired lines; operators responsive devices at different operators posit ons; and selecting mechanism for selecting operators responsive devices that are free for selection, the

.link connectors performing their line join- MORTON Li JOHNSON.

Witnesses: i I

. G. LrCRAGG, E. L. WHITE.

I Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D, 0. 

